The present invention relates generally to devices and methods for cushioning surfaces, and more particularly to devices and methods for cushioning or padding surfaces of compression plates applied to body parts during x-ray procedures, for example, during mammography, biopsies, and the like.
During mammography, a patient""s breast is placed under compression by opposing plates attached to a mammography unit. Once under compression, an x-ray may be taken to determine the presence or absence of suspect lesions in the breast tissue, e.g., calcifications or tumors. An important reason for compressing the breast during mammography is to provide a thinner cross-section of tissue for the x-rays to pass through. When the breast is compressed, it may provide optimal imaging of tissue abnormalities and/or may allow lower doses of x-ray radiation to be used, thereby reducing x-ray radiation exposure to the patient.
FIGS. 1, 2A, and 2B show a mammography unit 10, including a base 12 and a rotating assembly 14 that includes an x-ray source 16, a compression paddle 18, and an x-ray plate 20. The x-ray plate 20, often referred to as a xe2x80x9cbucky,xe2x80x9d is stationary relative to the rotating assembly 14, while the compression paddle 18 may be attached to an interchange assembly 22 that is movable relative to the x-ray plate 20.
As best seen in FIG. 2A, the x-ray plate 20 generally includes two patient contact surfaces, a primary tissue contact surface 24 and a front surface 26, as well as side surfaces 28. At least one of the side surfaces 28 may include an opening 30 into which an x-ray cassette 32 may be inserted. FIGS. 4A and 4B show attachments that may be placed on the x-ray plate 20 to enhance imaging, e.g., an attachment 40 for spot compression and an attachment 42 for magnification.
As best seen in FIG. 2B, the compression paddle 18 also generally includes two patient contact surfaces, a primary tissue contact surface 34 and a front surface 36, as well as two side surfaces 38. FIGS. 3A-3C show other configurations of compression paddles 44-48 that may have various shapes and sizes depending upon a patient""s anatomy and/or the type of x-ray view that is desired.
With the patient (not shown) leaning against the front surfaces 26, 36, the patient""s breast (also not shown) is placed on the primary contact surface 24 of the x-ray plate 20 and the compression paddle 18 is moved towards the x-ray plate 20 to compress the breast between the primary contact surfaces 24, 34. A series of x-rays may be taken of the breast tissue, e.g., involving moving the rotating assembly 14 and/or repositioning the patient""s breast after each film exposure.
One of the problems with mammography is that the patient may experience significant discomfort during compression of the breast. Because of this, some women may avoid having a mammogram taken, rather than experience the pain that may be caused during the procedure. Although patients may tolerate the pain caused by compression up to about ten to eleven (10-11) compression units, clinical mammography may involve up to sixteen to eighteen (16-18) compression units. If greater compression is used, the quality of the mammogram may be enhanced, thereby increasing the physician""s ability to detect cancers or suspect lesions. However, with greater compression comes increased discomfort.
U.S. Pat. No. 5,541,972, issued to Anthony, discloses a padding device that may be added to cover the front surface of an x-ray plate. Because the padding device is made from materials that may be radiopaque, the padding device is generally positioned to avoid disposing it within the field of the x-ray plate.
U.S. Pat. No. 5,185,776 discloses a radiolucent pad that is glued to a sleeve. An x-ray cassette may be inserted into the sleeve, a patient may be disposed against the pad, and an x-ray image obtained. The sleeve and pad are disposed of after the x-ray procedure. Disposing of the entire x-ray sleeve after a single use, however, may increase the cost of x-ray procedures.
Accordingly, improved devices and methods for increasing patient comfort during mammography and/or for allowing increased compression without substantially increased discomfort would be useful.
The present invention is directed to devices and methods for cushioning surfaces, for example, for cushioning or padding surfaces of compression devices applied to body parts during x-ray procedures, such as during mammography, biopsies, and the like.
In accordance with one aspect of the present invention, a compressible and/or resilient pad is provided for cushioning a compression surface of a mammography unit. The pad is formed at least partially from radiolucent material, and includes first and second surfaces. A radiolucent tape includes a first surface that is attached to the first surface of the pad, and a second exposed surface that includes a radiolucent pressure sensitive adhesive for removably attaching the exposed surface to an object.
Preferably, the tape is a double coated tape, e.g., including a polyester or polyethylene base film, and an acrylic adhesive on the first and second surfaces. The adhesive on the first surface may substantially permanently attach the tape to the first surface of the pad, while the adhesive on the exposed surface may allow attachment to an object, such as an x-ray plate, a compression paddle, or other compression device. A cover sheet may cover the exposed surface of the tape, the cover sheet being removable before attaching the exposed surface to an object.
In one embodiment, the entire pad may be formed from radiolucent material, while alternatively, the pad may include a radiolucent region, e.g., a central region, and a radiopaque region, e.g., a border around the central region. The pad may include one or more side regions adjacent the central region, at least one of which may include a slot therethrough. In a further alternative, the pad may include a window for providing access through the pad.
In accordance with another aspect of the present invention, an apparatus is provided for compressing a tissue structure using a compression device that includes a primary contact surface formed from radiolucent material, and one or more side surfaces extending laterally from the primary contact surface. The compression device may be an x-ray plate, a compression paddle, or an attachment to such devices. A pad, such as that described above, may be secured to the compression device. The pad includes a tissue contact surface formed from radiolucent material that may be removably secured against the primary contact surface, and one or more side regions removably secured along respective side surfaces of the compression device. In one embodiment, the pad may include a pair of side regions extending from opposing edges of the tissue contact surface. The side regions may extend around the compression device and connect to one another such that the tissue contact surface is secured adjacent the primary contact surface of the compression device with or without using an adhesive. In addition, or alternatively, the pad may include a front region removably secured to a front surface of the compression device. The front region may simply cover the front surface or it may be sufficiently long such that the front region and at least one of the side regions overlap to substantially secure the pad to the compression device.
In another embodiment, the pad may be a sleeve that may be received around at least a portion of the compression device. Preferably, the pad is sized to slidably engage the compression device sufficiently to secure the tissue contact surface adjacent the primary contact surface. The sleeve may include a top panel, side panels, a bottom panel, and/or a back panel. One or more side regions may include a slot therein corresponding to an opening in a side surface of the compression device, thereby providing access to the opening when the side region is secured adjacent the side surface, e.g., to insert an x-ray cassette into the compression device.
In accordance with yet another aspect of the present invention, a device is provided for attachment to a compression device of a mammography unit or a stereotactic biopsy unit. The device generally includes a pad formed at least partially from radiolucent material. The pad includes first and second surfaces, and markings for orienting a tissue structure applied against the second surface. The markings may include notches or indents in at least one of the first and second surfaces and/or in one or more edges of the pad. The markings may be radiolucent (i.e., detectable visually, but undetectable by x-ray). Alternatively, the markings may be radiopaque, e.g., printed on at least one of the first and second surfaces.
In addition, the device may include a layer of adhesive for removably attaching the first surface of the pad to the compression device. For example, a radiolucent adhesive may be applied directly to the first surface, such as a pressure sensitive adhesive. Alternatively, the first surface may include a texture, e.g., an inherent texture of the first surface or a texture applied to the first surface, to provide sufficient friction between the first surface and an object.
Preferably, the layer of adhesive includes a double coated tape attached to the first surface, as described above. Polyethylene tape may be preferred because of its elasticity, which may facilitate securing the device around corners of a compression device while minimizing creation of air pockets or creases that may be visible on an x-ray image. The device may be attached to a compression device and/or may include other features, e.g., similar to the embodiments described above.
Other objects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.